linux.git/drivers/base/core.c, branch v5.11-rc2

driver core: Fix a couple of typos

2020-12-09T18:29:47+00:00

These were just some minor typos that have crept in recently and are
easily fixed.

Reviewed-by: Rafael J. Wysocki 
Signed-off-by: Thierry Reding 
Link: https://lore.kernel.org/r/20201127104630.1839171-1-thierry.reding@gmail.com
Signed-off-by: Greg Kroah-Hartman

driver core: Delete pointless parameter in fwnode_operations.add_links

2020-12-09T18:14:48+00:00

The struct device input to add_links() is not used for anything. So
delete it.

Acked-by: Rob Herring 
Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-18-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Refactor fw_devlink feature

2020-12-09T18:14:48+00:00

The current implementation of fw_devlink is very inefficient because it
tries to get away without creating fwnode links in the name of saving
memory usage. Past attempts to optimize runtime at the cost of memory
usage were blocked with request for data showing that the optimization
made significant improvement for real world scenarios.

We have those scenarios now. There have been several reports of boot
time increase in the order of seconds in this thread [1]. Several OEMs
and SoC manufacturers have also privately reported significant
(350-400ms) increase in boot time due to all the parsing done by
fw_devlink.

So this patch uses all the setup done by the previous patches in this
series to refactor fw_devlink to be more efficient. Most of the code has
been moved out of firmware specific (DT mostly) code into driver core.

This brings the following benefits:
- Instead of parsing the device tree multiple times during bootup,
  fw_devlink parses each fwnode node/property only once and creates
  fwnode links. The rest of the fw_devlink code then just looks at these
  fwnode links to do rest of the work.

- Makes it much easier to debug probe issue due to fw_devlink in the
  future. fw_devlink=on blocks the probing of devices if they depend on
  a device that hasn't been added yet. With this refactor, it'll be very
  easy to tell what that device is because we now have a reference to
  the fwnode of the device.

- Much easier to add fw_devlink support to ACPI and other firmware
  types. A refactor to move the common bits from DT specific code to
  driver core was in my TODO list as a prerequisite to adding ACPI
  support to fw_devlink. This series gets that done.

[1] - https://lore.kernel.org/linux-omap/ea02f57e-871d-cd16-4418-c1da4bbc4696@ti.com/

Tested-by: Laurent Pinchart 
Tested-by: Grygorii Strashko 
Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-17-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Use device's fwnode to check if it is waiting for suppliers

2020-12-09T18:13:02+00:00

To check if a device is still waiting for its supplier devices to be
added, we used to check if the devices is in a global
waiting_for_suppliers list. Since the global list will be deleted in
subsequent patches, this patch stops using this check.

Instead, this patch uses a more device specific check. It checks if the
device's fwnode has any fwnode links that haven't been converted to
device links yet.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-14-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Add fw_devlink_parse_fwtree()

2020-12-09T18:10:21+00:00

This function is a wrapper around fwnode_operations.add_links().

This function parses each node in a fwnode tree and create fwnode links
for each of those nodes. The information for creating the fwnode links
(the supplier and consumer fwnode) is obtained by parsing the properties
in each of the fwnodes.

This function also ensures that no fwnode is parsed more than once by
marking the fwnodes as parsed.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-13-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Allow only unprobed consumers for SYNC_STATE_ONLY device links

2020-12-09T18:10:21+00:00

SYNC_STATE_ONLY device links only affect the behavior of sync_state()
callbacks. Specifically, they prevent sync_state() only callbacks from
being called on a device if one or more of its consumers haven't probed.

So, creating a SYNC_STATE_ONLY device link from an already probed
consumer is useless. So, don't allow creating such device links.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-10-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Add fwnode link support

2020-12-09T18:10:21+00:00

Add support for creating supplier-consumer links between fwnodes.  It is
intended for internal use the driver core and generic firmware support
code (eg. Device Tree, ACPI), so it is simple by design and the API
provided is limited.

Acked-by: Rob Herring 
Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-9-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "driver core: fw_devlink: Add support for batching fwnode parsing"

2020-12-09T18:10:20+00:00

This reverts commit 716a7a25969003d82ab738179c3f1068a120ed11.

The fw_devlink_pause/resume() APIs added by the commit being reverted
were a first cut attempt at optimizing boot time. But these APIs don't
fully solve the problem and are very fragile (can only be used for the
top level devices being added). This series replaces them with a much
better optimization that works for all device additions and also has the
benefit of reducing the complexity of the firmware (DT, EFI) specific
code and abstracting out common code to driver core.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-7-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "driver core: Don't do deferred probe in parallel with kernel_init thread"

2020-12-09T18:10:20+00:00

This reverts commit cec72f3efc6272420c2c2c699607f03d09b93e41.

Commit cec72f3efc62 ("driver core: Don't do deferred probe in parallel
with kernel_init thread") was fixing a commit 716a7a259690 ("driver
core: fw_devlink: Add support for batching fwnode parsing"). Since the
commit being fixed itself is going to be reverted, the fix can also be
reverted.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "driver core: Rename dev_links_info.defer_sync to defer_hook"

2020-12-09T18:10:20+00:00

This reverts commit ec7bd78498f29680f536451fbdf9464e851273ed.

This field rename was done to reuse defer_syc list head for multiple
lists. That's not needed anymore and this list head will only be used
for defer sync. So revert this patch to avoid conflicts with the other
reverts coming after this.

Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20201121020232.908850-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman